Secreted Phosphoprotein 1 Promotes the Development of Small Cell Lung Cancer Cells by Inhibiting Autophagy and Apoptosis
- 121 Downloads
This study aimed to investigate the expression of secreted phosphoprotein 1 (SPP1) on lung cancer cells and explore its underlying mechanism on autophagy and apoptosis which effect the development of lung cancer cells. GSE19804 related to lung cancer cells was screened from Gene Expression Omnibus (GEO) database, and we screened the 47 pairs of differential expressed mRNAs in lung cancer cells and adjacent tissues using microarray analysis. The expression of the core gene SPP1 was detected by qRT-PCR and western-blot. The transfection efficiency of lung cancer cells was detected by qRT-PCR and the expression of transfected group was tested by western-blot. Cell proliferation after transfection was tested by MTT assay and plate cloning experiment. The apoptosis rate of each transfection group was detected by flow cytometry. We use western-blot to test protein expression of autophagy-related proteins Beclin-1, LC3-I, LC3-II and p62 of each transfected group. Through analysis of GSE19804,the heat map showed SPP1 was the highest expressed in tumor tissues. qRT-PCR and western-blot detected SPP1 expression in lung cancer tissues was higher than that in normal adjacent tissues and was significantly increased in lung cancer cell lines. After transfection with pcDNA3.1-SPP1 (p-SPP1 group), siRNA1-SPP1 (siRNA1 group) and siRNA2-SPP1 (siRNA2 group), showed different expression of SPP1. Up-regulation of SPP1 enhanced cell viability and promoted tumor cell proliferation, while knockdown of SPP1 inhibited tumor cell proliferation. From the results of apoptosis rate, SPP1 inhibited the tumor cell apoptosis. However, in normal lung cell, SPP1 had no effect on cell proliferation and apoptosis. And to test autophagy-related proteins, we found that overexpression of SPP1 inhibited autophagy. High expression of SPP1 inhibited autophagy and apoptosis to promote the development of small cell lung cancer cells.
KeywordsSPP1 Small cell lung cancer cells Autophagy Apoptosis
This study was supported by Shandong Province Science and Technology Public Relations (No.2012GGE27122) and Science and Technology Program Project of Jinan (No. 201704093).
This study was funded by Shandong Province Science and Technology Public Relations (No.2012GGE27122) and Science and Technology Program Project of Jinan (No. 201704093).
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflict of interest.
All procedures performed in studies involving human participants were in accordance with the ethical standards of Qilu Hospital of Shandong University.
Informed consent was obtained from all individual participants included in the study.
- 5.He C, Klionsky DJ (2009) Regulation mechanisms and signaling pathways of autophagy. Annu Rev Genet 43:67–93. https://doi.org/10.1146/annurev-genet-102808-114910 CrossRefPubMedPubMedCentralGoogle Scholar
- 11.Heymann JJ, Bulman WA, Swinarski D, Pagan CA, Crapanzano JP, Haghighi M, Fazlollahi L, Stoopler MB, Sonett JR, Sacher AG, Shu CA, Rizvi NA, Saqi A (2017) PD-L1 expression in non-small cell lung carcinoma: comparison among cytology, small biopsy, and surgical resection specimens. Cancer 125:896–907. https://doi.org/10.1002/cncy.21937 CrossRefGoogle Scholar
- 17.Maiuri MC, Le Toumelin G, Criollo A, Rain JC, Gautier F, Juin P, Tasdemir E, Pierron G, Troulinaki K, Tavernarakis N, Hickman JA, Geneste O, Kroemer G (2007) Functional and physical interaction between Bcl-X(L) and a BH3-like domain in Beclin-1. EMBO J 26:2527–2539. https://doi.org/10.1038/sj.emboj.7601689 CrossRefPubMedPubMedCentralGoogle Scholar
- 20.Kabeya Y, Mizushima N, Ueno T, Yamamoto A, Kirisako T, Noda T, Kominami E, Ohsumi Y, Yoshimori T (2000) LC3, a mammalian homologue of yeast Apg8p, is localized in autophagosome membranes after processing. EMBO J 19:5720–5728. https://doi.org/10.1093/emboj/19.21.5720 CrossRefPubMedPubMedCentralGoogle Scholar